Wrinkle resistant cellulose fabric and method of production



3,041,199 WRINKLE RESISTANT CELLULOSE FABRIC AND NETHOD F PRODUCTION William S. Miller, Ashton-on-Mersey, and Kenneth Wild,

Middleton, England, assignors to Calico Printers Association, Limited, Manchester, England No Drawing. Filed July 20, 1960, Ser. No. 44,014 Claims. (Cl. 117-62) This invention is concerned with improved fibrous webs which have been treated to mitigate deleterious chlorine retention characteristics of the webs. More particularly, the invention is concerned with (a) finished textiles or other fibrous webs which comprise alkylene urea/ aldehyde resins without possessing deleterious chlorine retention properties, (b) new aqueous fabric treating compositions, and (0) methods for the treatment of textiles and other fibrous webs to simultaneously create desirable permanent effects therein and mitigate deleterious chlorine retention properties of the webs.

It is known to finish textiles by applying thereto condensation products of an aldehyde, commonly formaldehyde, with an amide, commonly urea, thiourea, ethylene urea, propylene urea, guanidine, dicyandiamide,

v melamine and the like and converting said condensation products to the insoluble state in situ. By suitable 'choice of starting materials and processing conditions,

a variety of commercially valuable effects can be obtained, particularly with textiles which are of cellulosic origin. These include improved dimensional stability, improved recovery from creasing, improved fastness of fugitive dyestuffs and durability to washing of mechanical effects such as glazing, embossing, beetling, schreiner ing, pleating and the like. One of the disadvantages of such treatments is, that to varying degree, depending on the choice of starting material and on the manner of application, the nitrogenous resins fixed on the textile material have a tendency to absorb chlorine from bleaching solutions with formation of labile complexes of resin and chlorine. These complexes are broken down when the textile is subsequently heated to temperature as, for example, in hot pressing, some at least of the decomposition product being hydrochloric acid. With cellulosic textiles, loss in strength occurs which may be severe with some resins and less so with others.

- Even with the latter, however, there is a cumulative effect with repeated bleaching and inevitably therefore, the useful life of the fabric is reduced.

The principal object of this invention is the provision ofnew improvements in treated fibrous webs which comprise alkylene urea/ aldehyde resins, but which do not, at the same time, possess deleterious chlorine retention properties. Further objects include:

(1) The provision of new and novel textiles which include resin finishes to impart to the fabrics desirable permanent effects, and also, as a permanent part of the fabric, chemically reactive groups which function during washing of the fabrics with chlorine-containing bleaching agents, and subsequent ironing or hot pressing, to render inactive any hydrochloric acid set free by the elevated temperatures of the hot pressing or ironmg.

(2) The provision of new textile treating compositions which contain a combination of one or more alkylene urea/aldehyde resins with a modifying agent which renders the resin finish which may be formed on textiles from said composition resistant to chemical degradation by chlorine containing bleaching agents.

(3) The provision of new processes for treating textiles or other fibrous webs with alkylene urea/aldehyde resin compositions in order to impart wrinkle resistance and other permanent effects thereto, and, at the same time, mitigating or preventing the simultaneous formation in the webs of deleterious chlorine retention characteristics.

Other objects and further. scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description, while indicating preferred embodiments of the invention is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

These object-s are accomplished according to the present invention by applying to a fibrous web of organic fibers a water-soluble, thermosetting alkylene urea/aldehyde precondensate and also an acid having the following structure:

wherein R is a radical selected from the group consisting of hydrogen and 1 to 6 carbon alkyl and R is a radical selected from the group consisting of alkylene, hydroxy alkylene and aryl, particularly monocyclic aryl, one to eight carbon alkylene, and one to eight carbon mono or dihydroxy alkylene, and subjecting the web with the applied precondensate and acid to conditions necessary to thermoset the precondensate to form in and on the web a resin finish which is water-insoluble and also insoluble to organic solvents encountered in drycleaning operations. This results in new treated fibrous webs which do not possess deleterious chlorine retention properties, composed of organic fibers having thereon a water-insoluble, organic solvent-insoluble finish comprising a thermoset, alkylene urea/aldehyde resin and an acid as aforesaid which constitutes a modifying agent for protection of the structure against deleterious effects of chlorine retention.

' The exact mechanism by which fixation of the modifying acid is brought about on the organic fiber is not clear. It may be due to reaction with reactive groups, e.g., hydroxyl groups, in the organic fiber or to interaction with the alkylene urea/aldehyde resin during the thermosetting operation. In any event, the invention provides for modification of the known finishing of textiles with alkylene urea/ aldehyde resins by the additional fixation in the fabric finish of an N-methylol monoamide of a dicarboxylic acid as aforesaid.

The modifying acid is conveniently applied to the fibrous web, along with the alkylene urea/aldehyde condensation product and fixed as a part of the finish at the same time as the condensation product is converted to a thermoset material. However, the modifying acid may also be applied separately, before or after, the application of the alkylene urea/ aldehyde material.

The success of the present invention is due to the discovery that hydrochloric acid degradation of cellulose or other organic fibers finished with amino-aldehyde resins can be reduced or even prevented by the presence in the fabric finish of one of the monoamide acids of this invention. This protection against degradation appears to be due to a reaction between the hydrochloric acid set free upon hot pressing and the alkali salt of the acid component, which results in formation of alkali chloride and the fabric-fixed carboxylic acid, which, being a weak acid, does not attack the cellulose as does hydrochloric acid. When the fabric is later washed in a liquor containing alkali, as in almost all domestic or commercial laundering operations, the alkali carboxylate is regenerated and is then ready to protect the fabric against further bleaching treating. Thus, the cycle can be repeated indefinitely.

A more complete understanding of the new products, compositions and processes of this invention may be had by reference to the following actual examples of operations conducted in accordance with the invention. In these examples, all parts and percentages are by weight unless otherwise specifically indicated.

Example 1 A bleached and mercerized cotton plain cloth of grey construction 80 X 80 of 30s/30s is saturated by being immersed in a water solution containing 4.5% of a precondensate of cyclic ethylene urea and formaldehyde,

' 0.5% of emulsified parafiin wax, 0.25% of a non-ionic softening agent, 1% of ammonium chloride and 0.5% of N-methylol succinamic aoid. After impregnation, the cloth is mangled so that it retains 80% of its own weight of impregnating solution. It is then dried in hot air (100 C.), following which it is heated for five minutes at 130 C. Finally, the finished cloth is Washed for five minutes at 50 C. in Water containing 0.1% sodium carbonate, rinsed in clear water and dried.

The resulting finished cloth is subjected to severe washing followed by three successive treatments in hypochlorite bleach solution and hot ironing. After the third ironing, the tensile strength of the cloth is tested and found to be 2.5% less than the tensile strength of the cloth before the bleaching and ironing treatments.

' In another case, the same cloth is treated in the same manner except that the impregnating solution contains no N-methylol succinamic acid. In this case, the bleached and ironed cloth is found to have lost 45% tensile strength as compared with its strength before the bleaching and ironing.

Example 2 The procedure of Example 1 is repeated using a water solution containing 30% of a precondensate of urea and formaldehyde, 0.5% of emulsified paraflin wax, 0.25% of non-ionic softening agent, 1% ammonium dihydrogen phosphate and 2% N-methylol phthalamic acid.

The resulting finished cloth after the bleaching and ironing treatments is found to havea tensile strength loss of 4.8% whereas the cloth finished without the N-methylol phthalamic acid in the solution is found to have a tensile strength loss of 34%.

The preferred amino-aldehyde resins for use in the present invention include ethylene urea-formaldehyde resins (sec 11.8. 2,373,136 and 2,795,513), and 1,3-propylene urea-formaldehyde resins (see U.S. 2,690,404). Additional examples of cyclic amino organic compound condensation products with aldehydes are found in Us. patents 2,370,839; 2,374,647; 2,700,032; and 2,764,573. Any of the resins referred to in these patents may be used in carrying out the operations of this invention.

The alkylene urea/ aldehyde condensation product is heat-reactive, i.e., will convert on being heated to a thermoset condition and is applied to the fibrous web in the stage of polymerization or condensation such that it may be dissolved in water. In order to aid in thermosetting or curing the condensation products to a water-insoluble and organic solvent insoluble stage, once applied to the fibrous web, the aqueous treating solutions prefer-ably should contain an acidic catalyst. A Wide variety of such materials have been developed and are known for use in catalyzing the curing of amino-aldehyde condensation products. Examples of suitable catalysts include free acids, e.g., hydrochloric, citric, phthalic and tartaric acids;a'cid-reacting metal salts, e.g., zinc nitrate, zinc chloride, magnesium chloride, zinc fluoroborate and acidreacting salts of ammonia or amines, e.g., ammonium chloride, ammonium dihydrogen phosphate, ammonium silico fluoride, amino-alkanol hydrohalides and the like.

plished simultaneously or in separate steps.

Other examples of suitable acid catalysts will be found in the disclosures of the patents referred to above. Usually, 1 to 10% by weight of the catalyst based upon the weight of the initial alkylene urea/ aldehyde condensation product is an effective amount for use in the operations of this invention.

The amount of the alkylene urea/ aldehyde resin incorporated in the fibrous webs will depend to some extent both on the specific resin used and upon the particular permanent effect desired to be created in the fibrous web. As little as 1% and as great as 50% by Weight of the condensation product based upon the dry weight of the fibrous Web may be employed, depending on the nature of the fibrous Web and the amount and type of permanent effect to be obtained. However, with broadcloth shirting material of cotton and similar relatively lightweight fabrics of cellulosic material, to which the invention is particularly applicable, an alkylene urea/ aldehyde resin concentration of between about 3 and 15% or even up to 25% by Weight is recommended.

A variety of different modifying acids may be used in accordance with this invention. These acids are the N- methylol derivatives of monoamides of dicarboxylic acids and are readily prepared from the latter by reaction with formaldehyde. While it is preferable to prepare the N- methylol acid before addition to the alkylene urea/aldehyde precondensate, it is possible to add the dicarboxy acid monoamide to the precondensate solution and bring about its reaction with formaldehyde to form the N- methylol derivative either in the solution or on the fibrous web after application of the treating solution.

Specific examples of compounds which may be used as the modifying acids for the purposes of this invention include the N-methylol derivatives of succinamic, phthalamic, hydroxy-succinamic, tartramidic, maleamic and oxamic acids. Also, the N-methylol monoamides of malonic; adipic; sebacic; terephthalic; 2,4-hexadienedioic; fumaric; 2,2'-diphenic; dimethyl malonic; phenyl succinic; [3,,8-diphenyl isosuccinic; a-methyl, (if-phenyl succinic; {i s-dimethyl glutaric and fl-phenyl glutaconic acids. Mixtures of two or more of the modifying acids may be used.

The amount of modifying acid incorporated in the treated fibrous webs may be varied. As previously indicated, the quantity of this material will depend to some extent upon the nitrogenous synthetic resin applied to the textile. Beneficial results against chlorine retention can be obtained with the use of as little as 0.1% by weight of the modifying acid. Satisfactory treated fibrous webs may include 0.1 to 20% by weight of the modifying acid and preferably about 0.1 to 5% by weight and especially 0.1 to 1%. Usually, the ratio of modifying acid to the alkylene urea/aldehyde resin, both in the treating compositions and in the final finished fabric, will be between about 1 to 20 and 1 to 5.

Once the aqueous treating solutions or dispersions have been applied to the fibrous webs, the webs are dried at a temperature of, for example, 50 to 150 C., and are then heated to convert the active resin-forming material into a thermoset resinous product and fix the modifying acid on the fabric. This is preferably accomplished at a temperature of about to 200 C. for about 1 to 15 minutes. Drying and curing can take place at the same temperature and in the same oven or dryer, if desired. Further, as indicated, the application of the alkylene urea/aldehyde resin and modifying acid can be accom- If accomplished separately, drying and heating should follow each of the solution applications.

No special equipment or unusual procedural methods are required for applying the treating compositions to fibrous webs. Thus, established padding or impregnation procedures may be used and these may be carried out in standard textile processing equipment. Likewise, the drying and heatingmay be carried out on standard textile handling apparatus. Furthermore, these fibrous web treattextile processing procedures such as water-proofing, calendering, embossing, pressing and the like. Other known finishing agents such as sizing agents, softeners, lubrieating material, water-repellent agents, moth-proofing agents, mildew-proofing agents, dyes, pigments and the like may be applied simultaneously or concurrently with the treating material of this invention. Since the alkylene urea/ aldehyde resins as referred to can also serve as fixing agents for dyestuffs, treatment of the fabrics as described can be used in conjunction with established dyeing or coloring operations.

In addition to padding or immersion of the fibrous webs in the described aqueous treating compositions in order to apply the treating materials to the fibrous webs, it is possible to apply the aqueous solutions or dispersions in any other suitable known fashion, e.g., brushing, spraying and the like.

Fibrous webs which may be operated upon in accordance with the present invention are formed of organic fibers. The webs may be in the form of non-woven fabrics, woven fabrics, knitted fabrics or any other similar sheet-like material made up basically of thread-like fibers or structures, whether in the form of a textile or other forms. The invention is particularly effective in treatment of webs composed .of fibers of cellulosic origin, e.g., cotton, viscose rayon, linen and the like but also any other fiber liable to be degraded by small amounts of hydrochloric acid are contemplated. The invention is also effective in treatment of webs composed partly of fibers of cellulosic origin and partly of other natural or synthetic fibers, e.g., protein fibers such as wool, silk, casein and the like, polyamide fibers, polyester fibers, polyvinyl alcohol fibers, polyacrylonitrile fibers and the like.

Having provided a complete description of the invenout the invention, the scope of patent protection to be granted the'invention is defined by the following claims.

We claim:

1. A resin treated cotton fabric resistant to chemical degradation by chlorine containing bleaching agents having thereon as a finish between about 3 and 15% by weight of ethylene urea-formaldehyde resin and between about 0.1 and 1% by weight of N-methylol succinamic acid. 7

2. A resin treated cellulosic fiber fabric resistant to chemical degradation by chlorine containing bleaching agents having thereon as a finish between about 3 and 15% by weight of an aminoplast selected from the group consisting of ethylene urea-formaldehyde resins and 1,3- propylene urea-formaldehyde resins and an acid (I) having a structure selected from the group consisting of:

wherein R is a radical selected from the group consisting of hydrogen and one to six carbon alkyl and R is a radical selected from the group consisting of alkylene, hydroxy alkylene, and aryl, the ratio of said aminoplast to said acid being between about 20 to 1 and 5 to 1.

3. A fabric as claimed in claim 2 wherein said acid is N-methylol succinamic acid.

4. A fabric as claimed in claim 2 wherein said acid is N-rnethylol maleamic acid.

5. A fabric as claimed in claim 2 wherein said acid is N-methylol phthalamic acid.

6. A fabric as claimed in claim 2 wherein said acid is N-methylol hydroxy succinamic acid.

7. A processv for finishing cotton fabric to impart Wrinkle-resistance thereto without causing the fabric to be prone to chemical degradation by chlorine containing bleaching agents which comprises impregnating cotton fabric with between about 3 and 15% by weight of a precondensate of ethylene urea and formaldehyde and with between about 0.1 and 1% by weight of N-methylol succinamic acid and heating the impregnated fabric at a temperature between about and 200 C. for between about 1 and 15 minutes to fix the precondensate and acid on the fabric.

8. A process as claimed in claim 7 wherein the heat treated fabric is washed in an alkaline solution to convert free carboxy groups in the'fabric finish to corresponding alkali metal carboxylate.

9. A process for finishing a cellulosic fabric to impart wrinkle-resistance thereto without causing the fabric to be prone to chemical degradation by chlorine containing bleaching agents which comprises impregnating a cellulosic fabric with a cellulose reactant selected from the group consisting of ethylene urea-formaldehyde condensation products and 1,3-propylene urea-formaldehyde condensation products and an acid (I) as defined in claim 2, the ratio of said cellulose reactant to said acid being between about 20 to 1 and 5 to 1, and heating the impregnated fabric at a temperature between about 100 and 200 C. for between about 1 and 15 minutes to said cellulose reactant and fix said acid on the fabric.

10. A process of finishing cotton fabric to impart wrinkle-resistance thereto without causing the fabric to be prone to chemical degradation by chlorine containing bleaching agents which comprises impregnating cotton fabric with between about 3 and 15% by weight of a water-soluble cellulose reactant selected from the group consisting of ethylene urea-formaldehyde condensation products and 1,3-propylene urea-formaldehyde condensation products and an acid (1) as defined in claim 4, the ratio of said Water-soluble cellulose reactant to said acid being between about 20 to 1 and 5 to 1, heating the impregnated fabric at a temperature between about 100 and 200 C. for between about 1 and 15 minutes to fix said reactant and acid on the fabric, and thereafter washing the finished fabric in an alkaline solution to convert free carboxy groups in the fabric finish into the corresponding alkali metal car-boxylate.

References Cited in the file of this patent UNITED STATES PATENTS 2,377,866 DAlelio June 12, 1945 2,898,238 Van Loo et al. Aug. 4, 1959 2,957,746 Buck et a1. Oct. 25, 1960 

7. A PROCESS FOR FINISHING COTTON FABRIC TO IMPART WRINKLE-RESISTANCE THERETO WITHOUT CAUSING THE FABRIC TO BE PRONE TO CHEMICAL DEGRADATION BY CHLORINE CONTAINING BLEACHING AGENTS WHICH COMPRISES IMPREGNATING COTTON FABRIC WITH BETWEEN ABOUT 3 AND 15% BY WEIGHT OF A PRECONDENSATE OF ETHYLENE UREA AND FORMALDEHYDE AND WITH BETWEEN ABOUT 0.1 AND 1% BY WEIGHT OF N-METHYLOL SUCCINAMIC ACID AND HEATING THE IMPREGNATED FABRIC AT A TEMPERATURE BETWEEN ABOUT 100* AND 200*C. FOR BETWEEN ABOUT 1 AND 15 MINUTES TO FIX THE PRECONDENSATE AND ACID ON THE FABRIC. 